Gemini 3.1 Pro Preview vs GPT-4.1 Mini

Summary of our 12-test suite (scores are from our testing and ranks show position among tested models):

• Gemini 3.1 Pro Preview wins 5 tests: structured_output 5 vs 4 (Gemini tied for 1st of 54; GPT rank 26 of 54), strategic_analysis 5 vs 4 (Gemini tied for 1st; GPT rank 27), creative_problem_solving 5 vs 3 (Gemini tied for 1st; GPT rank 30), faithfulness 5 vs 4 (Gemini tied for 1st; GPT rank 34), and agentic_planning 5 vs 4 (Gemini tied for 1st; GPT rank 16). These wins indicate Gemini is measurably better at schema/adherence tasks (JSON outputs), nuanced tradeoff reasoning, ideation quality, sticking to source material, and goal decomposition — all useful for production agents and structured pipelines.
• GPT-4.1 Mini wins 1 test: classification 3 vs 2 (GPT rank 31 of 53; Gemini rank 51). That indicates GPT-4.1 Mini is modestly better at routing/categorization in our classification tests.
• Ties (no clear winner): constrained_rewriting 4/4 (both rank 6), tool_calling 4/4 (both rank 18), long_context 5/5 (both tied for 1st), safety_calibration 2/2 (both rank 12), persona_consistency 5/5 (both tied for 1st), multilingual 5/5 (both tied for 1st). Practically, both models handle long context, multilingual output, persona maintenance, and basic tool-selection equally well in our suite.
• External/supplementary math signals (Epoch AI): Gemini scores 95.6% on AIME 2025 (Epoch AI) in our data vs GPT-4.1 Mini 44.7% on the same AIME test — a large gap favoring Gemini for very hard contest-style math. GPT-4.1 Mini posts 87.3% on MATH Level 5 (Epoch AI), a strong score for that benchmark; Gemini does not have a math_level_5 entry in the payload to compare directly. These external numbers confirm Gemini's strength on high-difficulty symbolic reasoning in our sample and GPT-4.1 Mini's competence on MATH Level 5.

Per the payload, Gemini 3.1 Pro Preview charges $2 input / $12 output per 1k tokens; GPT-4.1 Mini charges $0.40 input / $1.60 output per 1k. At 1M tokens/month (1,000 k-token units) Gemini output = $12,000 and input = $2,000 for a total of $14,000; GPT-4.1 Mini output = $1,600 and input = $400 for a total of $2,000. At 10M tokens/month Gemini totals $140,000 vs GPT-4.1 Mini $20,000. At 100M tokens/month Gemini totals $1,400,000 vs GPT-4.1 Mini $200,000. The 7.5× output price ratio means organizations at scale (10M+ tokens) will see six‑figure differences quickly — cost-conscious products, high-volume APIs, and startups should prefer GPT-4.1 Mini; teams prioritizing correctness of structured outputs, planning, and advanced reasoning may justify Gemini's higher spend.

Choose Gemini 3.1 Pro Preview if you need: high-fidelity structured outputs (JSON/schema), advanced strategic reasoning, creative problem solving, and top-ranked agentic planning — e.g., production agents, schema-driven APIs, complex decision support, or applications needing AIME-level math accuracy. Choose GPT-4.1 Mini if you need: a much lower-cost engine for chat, classification/routing, or large-volume apps where the 7.5× price gap ($12 vs $1.6 per 1k output tokens) would dominate your TCO. If you need both, consider routing high-value, high-correctness calls to Gemini and bulk/low-stakes traffic to GPT-4.1 Mini.